Oiling system for compressors



June 9, 1942. w. R. FREEMAN 2,235,426

OILING SYSTEM FOR COMPRESSORS Filed Jan. 51, 1941 INVENTOR W.R.FREEMANBY Patented June 9, 1942 ornmc; srs'rsM roa comaassoas Walter R.Jreeman,Clayton, Mo., asslgnor to Wagner Electric Corporation, St. Louis, Mo a vv. V

corporation of Delaware Application January :1, mr'serm No. 316,801 IClaims. (01. 230-2045) Y- My invention relates to compressorsfand moreparticularly to an oiling system therefor.

One of the objects of myinvention is to embody in an oiling system .fora compressor having a separate oil reservoir, improvedcontrol meanswhich will permit oil to flow to' the compressor and lubricate thepartsthereof only when the compressor is operating to dischargecompressed fluid. v

Another object is to provide in a compressor oiling system of the kindreferred to valve means for positively shutting oi the flow of oil tothe to" unload the compressor.

valve" assembly and conduit a leading to theair compressor causess'aidvalve to be subjectedto the air pressure in the receiver in'order'to be properly controlled. In addition to the shut-o3 valve in thevalve assembly N, there is also em ployed valve means for simultaneouslyventing the air reservoir'to the atmosphere through the air cleanerwheneverthe shut-oi! valve isclosed which the reservoir is unloaded isatoll and communicates with the reservoir at a point below the checkvalve I2. By venting thereacompressor whenever the'compressoris eitherun- I loaded or not being actuated and to accomplish thisnotwithstanding compressed fluid from the compressor may be acting onthe oil 'in the reservoir. V

Other objects of my invention will become ap parent from the followingdescription taken in connection with the accompanying drawing in whichthe single figure is a view of a compressor system having embodiedtherein my invention for controlling the flow of oil to thecompressor.

Referring to the drawing in detail, numeral I indicates a rotarycompressor of well-known design having a rotorshaft 2 driven by anysuitable means such as a pulley 2. In this compressor the fluid to'becompressed, which in this particular instance is air, enters thecompressor through the inlet 4 where it is compressed and dischargedthrough the discharge outlet 5. The discharged compressed air passesthrough the check valve. I into the conduit I where it is conveyed intothe top of an oil reservoir 8 by means of a tube 8 extending up into thereservoir, The upper end of the reservoir is connected by a conduit "tothe air receiver or tank It from which the compressed air may bewithdrawn to actuate anydevice desired. ,A check valve i2 is interposedbetween the reservoir andthe conduit II and prevents back flow of airunder-pressure into the reservoir. i I J The inlet of the compressor isconnected by a conduitxlS to an unloading valve assembly I which may beof any desired construction such as, for example, that shown inthe Fitesapplication Serial No; 301,102jfiled October 25, 1939,

for Valve mechanism for unloading compressor.

This valvevassembly is adapted to be controlled by the compressed air inthe receiver in order to cut oil communication from the atmospherethrough the air cleaner l5 to the conduit [3 whenever the pressure inthe receiver reaches a predetermined value say, for example, 100 poundsper square inch. Aconduit l5 between said 'e'rvoir toatmosphere when thecompressor isfun loaded, the compressor will run more freely since anyfluid discharged passes directly into the atchamber having fluidmosphere instead of into a under pressure therein; 7

Since the oil reservoir receives the discharged compressed air, the oilthereinis placedunder pressure "whenever the compressor is operated.

In order that the oil may be conveyed to the compressor bearings 1 andother moving parts, there is provided a conduit II which is connectedtothe bottom oi the reservoir by a passage In accordance from thereservoir to the compressor in sucha manner that the oil will-flow onlywhen the 'compressor is operatin and compressing air. At all other timestheoil from becoming choked with oil. As shown in the figure, there isprovided a valve casing 2| provided with chambers- 22 and 22-divided bya partition 24. Carried by this partition on the sideof the chamber 23is a valve seat 2I which surrounds the end of a passage 26 in thepartition for placing the conduit I. in communication with the chamber23 which chamber communicateswith the reservoir by means of the passage22 previously referredto. Cooperating with the I valve seat 25 is amovable valve element 21 positioned in chamber 23 and normally biasedonto the seat 25 by a spring".

The chamber 22 in the valve .casingcommunicates at one end with theconduit I coining from the exhaust port of the compressor and also withthe tube 9 leading to the top of the oil reservoir by way of passage 22yPositioned in the chamber 22 is a piston 20 carrying a projection itwhich.

extends through the partition in order to engage the valve element 21.-"The'piston has a loose fit with the wall or the chamber and'is Theconduit through y with my invention I provide means for properlycontrolling the flow of oil 'prevented'from commun'icating with thecompressor inorderto conserve, on the oil supply: and prevent thecompressor to flow to the compressor.

which connects the conduit 1 to the chamber 22 in order to block thisopen end when positioned at the left end of the chamber. However, whenthe piston is moved to the right end of the chamber, the passage 29 willbe uncovered and thus permit free flow of fluid from the conduit 1 totube I. Also, when the piston is in the latter mentioned position; theprojection 21 will engage and unseat the valve element 21.

In operation, when the compressor is not being driven the spring 29 willhold the valve element 21 seated and thereby prevent any oil fromentering the conduit is for passage to the compressor bearings andmoving parts. when the compressor is being driven and compressing air,

this compressed air will be discharged through the exhaust port and theconduit 1 to act on the piston 20. This air under pressure will forcethe piston to the right so that it will place the passage 29 in freecommunication with conduit 1 and permit the compressed air to enterthetop of the reservoir from where it can pass through the check valve l2to the air receiver. The movement of the piston to the right also causesthe valve 21 to be unseated against the bias of spring 22, therebyplacing the conduit I! incommunication with the bottom of the reservoirto permit oil to flow to the compressor bearings and work- I 2,285,420adapted to engage the open end of the fltting 22 predetermined valuetion. Thus it is seen that, notwithstanding the fact that air underpressure may be present in the oil reservoir and acting on the oil atthe time that thecompressor is no longer driven, the flow of oil will becut off. Therefore-under all conditions except when the compressor isoperating and discharging compressed air, communication between the oilreservoirand the compressor will I always-be cut oil. Therefore, thereisno possi-- bility of too much oil being forced into thecompressor whenthe compressor is no longer driven (rotor rotating) and there is stillair under pressure in the reservoir. In prior constructions wherein theair pressure in the oil reservoir is employed to control a valve forshutting off the flow of oil, the flow of oil would not be stopped underthese conditions.

Being aware of the possibility of modifications go in the particularstructure herein described with lag parts. 'The piston will always bemaintained inthe right hand end of the chamber 22 wheni ever thecompressor is discharging compressed air, due to the, fact that thiscompressed air in flowing to the reservoir will impinge on the pistonand maintain it in such position. The amount of oil being fed to thecompressor through pipe I! will only be suflicient for properlubrication and to replace the oil being carried out of the compressorwith the compressed air.

The amount of oil is regulated by the size of the passage in the rotorshaft 2 through which the oil is fed to the compressor. As long as the Ythe exhausted compressed fluid from the com-- proper level of oil ismaintained in the reservoir all the oil will never be forced out of thereservoir as oil is being continuously returned to the reservoir as itis fed therefrom to the compressor.

When the air pressure in the'receiver reaches the predetermined valuenecessary to operate the unloading valve in the valve assembly ll, the

inlet to the compressor will be shut 0!! iromate mosphere and thecompressor will thereby be unloaded. .Simultaneously with the. cuttingoil of the admission of air to the compressor, the oil reservoir willalso be placed in communication with the atmosphere and reliev'e 'theoil reservoir of the air under pressure." As soon asthe, comvolume ofcompressed air, the spring 2! wiil'bepressor discontinues dischargingany appreciable come ei'fective'to seat the valve element'21 since thepiston 30 is no longer held by any compressed air in the position tomaintain the valve 21 uncommunication between the oil reservoir and theconduit l2. and thus prevent any oil from passing to the compressor. a i

If the compressor should be stopped, that is no longer driven by ,thepulley 2 when the compressor inlet port is not shut oil! by means of theshut-off valve, the valve element 21 will, nevertheless, be seated, andoil will no longer-be able Underthese conditions the air. pressure inthe oil dome is not vented to atmospheresince the compressor unloadingvalve vwas not shut of! due to the fact that the air in'the receiver hadnot reached the This seating of the valve will cut oi! Having fullydescribed my invention, what I I claim .as new and desire to secure byLetters Patent oi the United States is:

1. In apparatus of theclass described, a fluid compressor, an oilreservoir connected by a conduit with the compressor for lubricating themoving parts thereoiya conduit for conveying pressorhfa valve forcuttingofl' the flow of 011 between thereservoir and the compressor, and

means comprising a movable member so associated with the. fluidconveying conduit that it will be acted on and moved by the dischargedcom-- pressed fluid. flowing through the conduit and thereby causethevalve position. V s s 2. In; apparatus of the class described,a'fluid compressor, an oil reservoir connected by a conduit with thecompressor for lubricating the moving parts thereof, a conduit'forconveying the exhausted compressed fluid from the compressor through thereservoir, a valve for cutting oi! the flow of oil between the reservoirand the compressor, and means for opening thevalve comprising a memberso associated with the fluid conveying conduit that the dischargedcompressed fluid will impinge thereon and cause said member to be movedto open the valve before said compressed fluid'passes to the,reservoir.-

3. In an intermittently operated fluid compressor system having-adischarge conduit and an oil reservoir for supplying the moving parts ofthe compressor with lubricant and which is so associated withthecompressor that discharged compressed fluid acts on the oil in thereservoir discharge compressed fluid and notwithstanding compressedfluid maybe in the reservoir, said means comprising a-valve biased toclosed position and a member so associated with the discharge conduit.that it will be contacted and moved by the compressed fluid'when flowingthrough the conduit to thereby open the valve;

4. In apparatus of the class described, a fluid compressor, an oilreservoir connected by a conduit with the compressor for lubricatingthemoving parts thereof, a conduit for conveying 'the exhausted compressedfluid from the compressor, a valve for cutting oi! the flow of oilnecessary for such operato 'be moved to open to forcev it tothecompressor, means for peventing oil from flowing tothe compressor movingparts when the'compre'ssorv is not operating tobetween the reservoir andthe compressor, and bores, conduits for connecting one-of said boresmeans for opening the valve comprising a-.cham-' to the oil reservoirand to the compressor for her in the fluid conveying conduit means andtherebvconveyi'ngoil tothe movingparts of said having spaced openingsone "ofywhich'fcommuni-r f compressorfa" valve in said here for cuttingofl cates with the portion of the conduit th fjflowflof oiL a spring forseating} the valve, ing from the compressorrandi n i 1: connectin'gtheothe -bore tothe communicates with the po'rti means leading to 'thereserporr member in said chamber operati 1y c to the valve, saidmember-Iaapted to be' pos tioned between the two openings whe is closedand to be moved to aigp'ositio cover the second opening by the lorecharged compressed fluid and there!) valve.

5. In apparatus of the {c1 compressor provided with an. exha an oilreservoir, a receiver conn 'cted oi the reservoir, a casmg i pp'g boreandeprovided with a projection ng, the valve; said piston. when theed'by the spring being so positioned the path offlowof compressed fluidompressoryto the I reservoir whereby 0r, unseati am? a ti willimpinge.onthe piston and cause ,ee valveto open position, the valveitiongof-said-"pis'ton being such as to I r? to the reservoir.

WALTER R. FREEMAN,

and to the 1 reservoir; agp m d fluid from the, compressor when it

